Electric discharge device and system



Feb. 8, 1949. F. M. BAILEY ELECTRIC DISCHARGE DEVICE AND SYSTEM 2Sheets-Sheet 1 Filed Dec. 5, 1945 Inve'nbofi:

a B M .m c n H His Attorneg.

Feb. 8;1949. F. M. BAILEY 2,461,250

ELECTRIC DISCHARGE DEVICE AND SYSTEM Filed Dec. 5, 1945 2 Sheets-Sheet 2{4 V i U '7 "I J3 J2 J2 CRYSTAL OSC/LL A701? 66 NEUTRAL a! If Q2 0 5 w'4 HisAotor-neg.

Patented Feb. 8, 1949 ELECTRIC DISCHARGEDEVICE AND SYSTEM 7 Francis M.Bailey, Scotia, N. Y., assignor to General Electric Company,

York

a corporation of New Application December 5, 1945, Serial No. 632,9 7?

My invention relates to improved electric discharge devices and systemstherefor, and particularly to improved phase modulation dischargedevices and systems.

In a known system of phase modulation a polyphase carrier wave isemployed for energizing two sets of control electrodes which togetherwith suitable focusing electrodes produce a disk of electrons having arufiled edge. The rufile or deflection at the edge of the disk isessentially sinusoidal in form. Due to the polyphase energization of thesystem of electrodes the sinusoidal wave advances around the electrondisk at the carrier frequency. An appropriate electron collectingelectrode system receives the electrons of the disk selectively inaccordance with the progression of the sinusoidal wave at the edge ofthe disk to produce an output voltage at the carrier'frequency. Thisvoltage is modulated by a modulating magnetic field perpendicular to theplane of the disk of electrons to advance or retard the sinusoidal waveat the edge of the disk with respect to its unmodulated position. Aswill be readily appreciated by those skilled in the art, an alternatingmodulating signal is eifecz tive continually to advance and retard thephase position of the sinusoidal wave at the edge of the electron disk.

An object of my invention is to provide such a phase modulating electrondischarge device having certain operating advantages and which, inaddition, is less difiicult to manufacture.

In accordance with an important aspect of my 17 Claims. (Cl. 250-275)invention, the polyphase carrier voltage supply is provided with aneutral terminal and the discharge device is provided with one set ofcontrol electrodes for energization from the polyphase carrier voltagesupply, and with a relatively simple control electrode structure forenergization in accordance with the voltage of the neutral terminal ofthe carrier voltage supply.

It is an object of my invention to provide a new and improved electricdischarge device and system.

It is another object of my invention to provide a new and improvedelectric discharge device for producing phase modulation of a carrierwave.

It is a still further object of my invention to provide a new and simpleelectrode structure for discharge devices of the type described above.

Further objects and advantages of my invention will become apparent fromthe following de-' scription when taken in connection with theaccompanying drawings and its scope will be pointed out in the appendedclaims. I

In the drawings, Fig. 1 is an elevational view of an electric dischargedevice embodying my invention; Fig. 2 is an enlarged view, in section,of a portion of the electric discharge device shown in-Fig. 1 showing indetail the electrode assembly; Fig. 3 is a sectional view taken alongthe line 33 of Fig. 2; Fig. 4 is a sectional View taken along the line44 of Fig. 2; Fig. 5 is a development of one of the electrodes of thedevices shown in Figs. 1 to 4; Figs. 6 and 7 illustrate schematicallythe electron pattern under certain operating characteristics of thedevice; Fig. 8 illustrates diagrammatically a frequency modulatingsystem embodying my invention; and

5 Fig. 9 is a development of a three-phase collecting electrode system.

Referring now to Figs. 1 to 4 of the drawings, I have shown my inventionembodied in an electric discharge device including an evacuated envelopeI to the lower end of which is secured a conventional base 2 including aplurality of contact prongs 3 and an orientation protuberance 4. Theelectrode assembly of the discharge device which is supported from thestem press (not visible in the drawing) by lead-in conductors 5 will nowbe described with particular reference to the enlarged views of Figs. 2to 4. The assembly includes a pair of concentrically arranged anode orcollecting electrode members 6 and I which are clamped between a pair ofmica washers 8 and 9'by the planar marginal portions of a pair offocusing and modulating electrode elements l0 and Il. The electrodes l0and II and washers 8 and 9 are clamped together at spaced points bysuitable connecting links I2, which are secured at opposite ends toangle members l3 which are, in turn, secured to the marginal portions ofthe electrode members I 0 and II. The members l0 and II are formed of amaterial of reasonably high permeability such as steel, and compriseplanar marginal portions and centrally located circular flange portions14 and I5 defining central openings of gradually decreasing diameter.The members Ill and II are assembled with the flange portions l4 and i5directed inwardly to provide a control gap between the inner endsthereof. V

A polyphase control electrode assembly is positioned in the openingdefined by the flange portion 14 of electrode [0 by means of a micawasher I6 supported from the lower side of the electrode Ill by threesupporting members I'!, which are welded or otherwise secured to theflange portion l4 andwhich are provided with projections l8 bent overagainst the outer surface of the washer [6. The electrode assemblyincludes a hollow cylindrical focusing electrode 19 having a flangedlower end portion 2! clamped to the inner surface of the washer l6.Surrounding the focus ing electrode is an assembly of controlelectrodes, which, in the specific embodiment illustrated, in-

cludes thirty-six wire-like elements 2| supported v The particular tubeillustrated is designed for energization from a three-phase carriervoltage supply and the electrode members 2| are, therefore, arrangediinthree sets, withthe individual conductors each conductively connectedtogether andxmutuallyinsulated with respect to the conductors of'theother sets. In order to accomplish this electrical connectiorneach. ofthe conductors 2| is provided with a radiallyextending portion forconnection with a conducting disk. As fllustrated in the. drawing, everythird conductor is connected with a conducting apertured disk 23. Theconductors adjacent these conductors on one side are connected withasecond conducting disk 25 and the remaining conductors are connectedwith a third disk 25. These disks are insulated from one. anotherandirom the electrode I! by suitable insulating disks '26 The disks 23,-24 and 25, each provides a common terminal for the respective set ofconductors, there being three sets. These disks and the respective setsof conductors, which are mutually insulated, are connected withdifferent ones of thelead-incon-- ductors by conductors 21, 2% and 28,respectively. The radially extending portions of electrodes 2i connectedwith the different treminal disks 23, 25 and 25 are located at differentlevels so that the stacked arrangement of terminals illustrated isprovided.

'An electrode assembly is supported from the upper electrode I i in amannersimilar to that just described in connection with the lowerelectrode Ill. The upper assembly includes a supporting mica washer 36to which is secured a cylindrical focusing electrode 3!, which isidenticalwith the iocusing'electrode it of the lower assembly. Thewasher Si! is supported from the disk H by suitable members 32, whichmay be of the same construction as the members ii. In the upper assemblya single planar electrode 33 of annular form and having a surfacesubstantially co-extensive with that occupied by the radial portions ofthe wire-like electrodes 2! is provided. This electrode is supportedconcentrically; and in insulated relation, with respect to the focusingelectrode 3i by means of a plurality of supporting wires 34 (three inthe illustrated embodiment), which are secured to an upwardly extendingcollar 35 on the electrode 33, and which are bent over at their upperends to engage the upper surface. of the mica washer 30. The wires 35clamp the electrode 33 against the lower surface of an insulatingWasher'B-E, which is held in position on the focusing electrode 3! bycollar 3! secured to the outside of the focusing electrode M. The washer36 centers the focusing electrode 3! and the control electrode 33 withrespect to the elec-v trode [6. A supply connection for the control tendfrom the lower end thereof.

4 electrode 33 is provided by a conductor 38 which extends through theupper washer 3B.

A source of electrons is provided in the region between the inner endsof the focusing electrodes l9 and El to radiate electrons outwardlyradially between the upper ends of the control electrodes 2i and theplanar electrode 33 to form a disk of electrons. This source is providedby an indirectly heated cathode sleeve 39, which is supportedconcentrically within the focusing electrodes is and 3! by means of theinsulating washers it and St].

The cathode may be provided with an oxide coating and heated by aninsulated heater element received within the sleeve 39 and provided withterminm conductors 38 and ii, which ex- The terminal conductors 453 and'll are connected with separate ones of the lead-in wires 5 and thecathode sleeve is connected by conductors 32 to one of these lead-Upper'iocusing electrode 3: is connected with lower focusing electrodel9 and to a lead-in conductor 5 by conductors 43 and 54 shown in Fig. l.The upper planar control electrode 33, which in operation is connectedwith the neutral" of the polyphase carrier supply voltage, isconnectedto a lead-in conductor 5 by a conductor t5, shown in Fig. l,which connects with conductor 38. s

The upper and lower focusing and modulating electrodes id and ii areelectrically connected together by the links :2 and to a lead-inconductor 5 by a conductor 46 secured to one of the angle members [3. cc I A cylindrical shield 41 of substantially the diameter of the lowersupporting washer Iii is secured to the lower electrode ii andelectrically connected thereto. The member ll shields the conductors 27,2'8 and 29 which are adapted to be energized from the polyphase carriersupply voltage from the output connection which are connectedrespectivelywith the anodes or collecting electrode membersfi and i. p

In Fig. i only, the supply conductors 2i and 28 connected with thepolyphase electrode system are visible, and only .conductor 53, which isconnected with the collecting electrode 6, is shown on the exterior ofthe shield member. It .will be understood that the-conductor Q9 of Fig.2 connects the collecting electrode 2 with a separate lead-in conductor5 and that the conductor 29 is connected with a lead-in conductor.

The modulation of the output voltage appearing across the collectingelectrodes 6 and l is effected by a magneticfield produced between theopposedend portions of the flanges l4 and ii": of themodulating andfocusing electrodes .1 Sand ll. As indicated earlier in thespecification, these membersare formed of amaterial of high p.ermo-,ability and provide a magnetic circuit for a modulating coil iii! whichsurrounds the envelope of the device in the region, of the outer edgesof the electrodes it and I 1. They serve to carry the magnctic flux o fcoil 5d inward and to ooncentrateit at right angles to theelectron discin .a circular region J'ustoutsideof and between the peripheries ofplanar electrode 33 and the electrode assembly 2 l, 22. V

Inforder that the 'electronswmay be collected selectively by theelectrodes 5 and 'l in accordance with 'the deflections produced by thevarious electrodes of the control system, the inner- .collectingelectrode fi is .provided 'with two,se ts..5.l and 52 of substantiallyrectangular openings. As indicated in the drawing, the openings of bothspect to each other on oppositesides of a median line. The spacingbetween adjacent-openings in each set is equal to the width ofthe'openings so that each opening of one set is opposite a space betweenadjacentopenings of the otherset.

The manner in which the electric discharge de-. vice of the illustratedembodiment of my invention operates to phase modulate a carrier voltagewave will now be briefly described. The electrons emitted from thecentral portion of the cathode sleeve 39 pass radially outwardly betweenthe op-' posed ends of. the cylindrical focusing members I 9' and 3| andthrough the region bounded on one side by the annular planar electrode33 and on the opposite side by the polyphase system of controlelectrodes including the wire-like control members 2 l. The electronsnext pass between the opposed ends of the focusing and modulatingelectrodes Ill and l l and continue to the collecting electrodes 6and 1. The first focusing electrodes l9 and 3| assist in neutralizingthe space charge around the cathode and also tend to confine t eelectrons to a relatively narrow region in an axial direction. With thecontrol electrodes 2| connected to provide a three-phase system, arotating electrostatic field is produced in the region between theradial portions of these electrodes and the face of the annularelectrode 33, which latter electrode is adapted to be connected to theneutral of the carrier voltage supply and which may therefore be termeda neutral plane electrode. This field is effective to produce adeflection of the electrons in an axial direction and provide asinusoidal ruffie at the edge of the electron disc having a spacedistribution determined by the space distribution of the controlelectrodes 2!. With the thirty-six electrodes provided in theillustrated embodiment, the edge of the disc takes the form of asinusoidal ruflle made up of twelve complete cycles. A diagrammaticrepresentation of the electron disc is shown in Fig. 6 in which the wallbounding the openin in the center represents the surface of thecathode39 and the control electrodes 2| are indicated diagrammaticallybya circumferential array of equally spaced dots 2|. The rufiled disc isbrought to a relatively thin edge by the electrostatic focusing actionof the electrodes l and H.

The manner in which the electrons are selectively received by thecollecting electrodes 6 and 1 will be readily understood from aconsideration of Fig. 5 in which a portion of the electrode 5 has beendeveloped.

Referring to Fig. 5, two sinusoidal waves 53 and 54 having the spacialdistribution of the wave at the edge of the electron disc have beenrepresented with respect to the developed portion of the electrode 6.The wave 53 represents the edge of the electron disc at an instant whenessen tially all of the electrons pass through the openings 5| and 52.Under. these conditions. the voltage of the collecting electrode 1 is amaximum and the voltage of the electrode 6 a minimum. The

dotted curve 54 represents the edge of the disc displaced 180 degrees.with respect to the edge of the disc represented bythe curve 53.It'will .be

noted that with this displacement essentiallyall.

the electrons are collected by the electrode 6 and that none of theelectrons passes through the openings 5! and 52 to be collected by theelec trode 1. Under these conditions, the voltage of openings 5| and 52are correlated directly withthe'number of control electrodes of thepolyphase electrode system and the number of phase groups in which theyare arranged; The dotted curve 54 represents the edge of the disk at aninterval of time later than the curve 53 corresponding .to a half cycleat the carrier frequency. In other words, the voltage of each of thecontrol electrodes 2| positionedopposite the crests of the waves asillustrated in Fig. 6 have changed from-a positive maximum to a negativemaximum during the interval of time during which the edge of the dischas changed from the configuration represented by curve 53 to thatrepresented bycurve 54.

In addition to the change in shapeof the electrons at the edge of thedisc due to the rotating field produced by the polyphase system ofelectrodes and the neutral plane electrode 33, the wave at the edge ofthe disc may be advanced or retarded by the application of voltage tothe modulating coil 55 which produces a magnetic field be-.

tween the opposed ring-like edges of the focusing and modulatingelectrodes H3 and H. As will be understood by those skilled in the art,an axial magnetic field will deflect the electrons tangentially. Adiagrammatic representation of the effect on the electron disc of aunidirectional magnetic field of predetermined magnitude is illustratedin Fig. 7 Where the edge portion has.

been rotated in a clockwise direction with respect to the electronsmaking up the inner portion of the disc. It is apparent, therefore, thatthe distribution of the electrons collected by plates 6 and I in thisinstance is dependent not only upon the electrostatic field produced bythe polyphase system of control electrodes 2| and the planar electrode33 but also on the modulating electromagnetic field produced between theopposed edges of the focusing and modulating electrodes I0 and l I. Itwill be understood by those skilled in the art that an alternatingmodulating voltage applied to the coil 55 will cause a continual advanceand retard of the wave at the edge of the electron disc with respect tothat which it would occupy in the absence of a magnetic field, with theoverall result that both phase and frequency modulation of the voltageappearing between electrodes 5 and 7 are produced. However, since aunidirectional voltage of constant magnitude applied to modulating coil50 produces pure phase modulation of the output voltage betweenelectrodes 6 and l, the tube is essentially a phase modulation tube.

In Fig. 8 I have illustrated a frequency modulating system embodying myinvention. In the system shown in Fig. 8 the discharge device 55 is adiagrammatic representation of the device described previously inconnection with Figs. 1 to '7. Electrode 51 corresponds to the outercollecting electrode 7; electrode 53 corresponds to the inner sponds tothe modulating coil 50 shown in Fig. 1.-

' The discharge device as described above is connected in afrequencymodulation system in the following manner. A voltage supply. formaintaining the various electrodes at appropriate direct currentvoltages is provided by voltage dividing resistors 51, 68, 69, I and 1!connected in series between a ground connection. I2 and the Positiveconductor '53 ofa source of direct current voltage. High frequencyicy-pass capacitors! are connected between one terminal of each of thevoltage dividing resistors and ground. As illustrated in the drawing,the cathode 65 is connected to the direct current ground. The insidefocus electrodes 53 and 64 are connected to'the positive terminal ofresistor 67 which may be at -a positive voltage of the order of voltsandthe outside focusing and modulating electrodes 6"!- and 62 are connectedto the positive terminal of resistor 68 and may be maintained at avoltage of 59 volts. The neutral plane. electrode 33" is connected tothe positive terminal of voltage dividing resistor 68 which may be 70volts positive, for example. 'The positive terminal of voltage dividingresistor Ill is connected to the neutral terminal of the polyphasecarrier supply voltage by conductor 16 to provide a direct currentvoltage differential between the neutral plane electrode 3| and thepolyphase system of electrodes 2!", which are energized by thethree-phase carrier voltage supplied by a single-phase to three-phaseconversion circuit 15. The conversion circuit '55 as illustratedisenergized by the output of a single-phasecrystal oscillator illustrateddiagrammatically at 16.

The collecting electrodes 5? and 58 areconnected together by acenter-tapped output coil H, which forms the primary winding of anoutput transformer 18 having a secondary winding 79 connected to afrequency multiplier and amplifier circuit, illustrated diagrammaticallyat Bil, which supplies the modulated carrier to an antenna 8|. Theprimary winding '17 is shunted by a capacitor 82 to provide anoscillatory circuit resonant at the carrier frequency. The mid-point ofthe transformer H is connected to the positive terminal of the voltagedividing resistor H, which may be at a suitable voltage, such as 250volts.

In order to suppress secondary emission of electrons by the electrode51, a self-biasing circuit including a parallel resistor 83 and acapacitor 84 is connected in the circuit with the inner collectingelectrode 58 to maintain it at a substantial negative direct currentvoltage with respect to the outer collector electrode 5?. The modulatingcoil 66 is energized from a suitable source of signal voltage, such asthe output of an audio amplifier indicated diagrammatically by the nu-:l

meral 85.

The operationof the system illustrated in Fig. 8 is believed to followdirectly from the detailed description of the operation of the dischargedevice of Figs. 1 to 4. The utilization of a carrier supply having aneutral terminal and a discharge device employing a neutral planeelectrode renders it possible to interpose a direct current voltagebetween these two electrode systems so that the undefiected edge of theelectron disc may be lined up with the line separating the two groups ofopenings El and 52 of the inner collecting electrode, thus producingsymmetrical alterhating voltage between the outputelectrodes 51 and 58.7 It will be apparent that the present invention, in addition toaffording the advantages just described in connection with the system ofFig. .8, provides a tube with many advantages over the prior art,particularly from the standpoint of staggered with respect to theopenings 86.

simplicity of construction. .Some of the important. featurescontributing to the simplicity are theuse of the neutral plane electrodeand the compactassembly in accordance with which the inner focusing andcontrol electrodes are supported from the outer focusing and modulatingelectrodes vill and H as shown in Fig. 2. The assembly ofthe polyphaseelectrodes and assoelated terminal discs provided is also a feature ofthe invention.

. The collecting electrodesoi the discharge device may be constructed toprovide a three-phase output. In Fig. 9 cylindrical electrodes of thistype have been developed into a planar View. The inner. electrode,designated by the numeral 6', is in general similar to the innercollecting electrode 6 as shown in Fig. 2. However, instead of twelveopenings in each set, the structure includes .three sets of three eachelectrically displaced from the preceding set by a distancecorresponding to 120 electrical degrees or two-thirds of the width ofone of the openings. Since the displacement precludes the possibility ofusing twelve openings, the total number of openings is reduced to nine,

' and'a portion of the cylinder is accordingly unused. As shown'in Fig.9, the collecting electrode includesin the first phase group threeopenings 86 above the center of the electrode and three openings 87below the center of the electrodeand As in the case of electrode ihthewidth of the openings is equal to the space between them. The second setof openings, corresponding to the second phase ofthe output, aredisplaced 120 electrical degrees with respect to the openings 86 and 81.

As indicated, the first opening of the upper set 38 of the second groupis displaced from the last opening 8'! of the preceding phase group. Ina similar manner, the first opening of the upper set of openings 83 ofthe third phase group is displaced 120 degrees with respect to the lastopening of the lower set 93 of the second phase group. The loweropenings of the third group are designated by the numeral 9!. In orderthat the displaced voltages may be collected and supplied to separateoutput terminals, the collecting electrode corresponding to the outerelectrode 1 of 'Fig. 2, for example, is formed in three sections Ilocated respectively behind the three groups of displaced openings.These sections, designated by-the -numerals'92, 93 and 94, are indicatedby dotted lines in Fig. 9. It will be understood that three outputcircuits will be provided for the electrode system of Fig. 9 with oneterminal of each circuit connected to the common electrode 61, and theother terminal of each of the circuits connected to the three electrodesections 92, 93 and 94. a V

While I have shown and described a particular embodiment of myinvention, it will be obvious to those skilled inthe art that changesand modifications maybe made Withoutdeparting from my. invention in itsbroader aspectsand I, therefore, aim in the appended claims to cover allsuch changes and modifications as .fall within the true spirit and scopeof my invention. 7 r

WhatI claim as new and desire to secure by Letters Patent of the UnitedStates is:

v1. An electric discharge device comprisinga source of electronsincluding means for confining said electrons in a generally planarregion, said means including electrode means positioned on oppositesides ofsaid region, aplurality of control electrodessupported inmutually spaced and insulated relation in a'p'lane on one side of saidregion and parallel thereto, a substantially planar control electrodelying in a plane on the opposite side of said region and in opposedrelation to said plurality of control electrodes, and a pair ofcollecting electrodes for selectively collecting electrons emitted bysaid source in accordance with the energization of said controlelectrodes.

2. An electric discharge device comprising a source of electronsincluding means for confining said electrons in a enerally planarregion, said means including electrode means positioned on oppositesides of said region, a plurality of control electrodes supported inmutually spaced and insulated relation in a plane bounding one side ofsaid region, a substantially planar electrode lying in a plane boundingthe opposite side of said region and in opposed relation to saidplurality of control electrodes, and collector electrode means, saidcontrol electrodes being supported between said source and saidcollector electrode,

means.

3. An electric discharge device comprising a source of electronsincluding means for confining said electrons in a generally planarregion, said means including electrode means positioned on oppositesides of said region, a plurality of control electrodes supported inmutually spaced and insulated relation on one side of said region, asubstantially planar control electrode supported on the opposite side ofsaid region abutting said plurality of control electrodes, a pair ofcollecting electrodes for selectively collecting electrons emitted bysaid cathode in accordance with the energization of said controlelectrodes.

4. An electric discharge device comprising an;

elongated cathode, a'plurality of electrodes supported in mutuallyspaced and insulated relation in a circular array concentric with saidcathode and lying in a plane substantially perpendicular to the axis ofsaid cathode, a substantially circular electrode supportedconcentrically with said cathode and spaced longitudinally of saidcathode with respect to said plurality of electrodes, and collectorelectrode means surrounding said cathode and said control electrodes.

5. An electric discharge'device comprising an elongated cathode, aplurality of control electrodes supported in mutually spaced andinsulated relation in a circular array concentric with said cathode, asubstantially circular electrode supported concentrically with saidcathode and spaced longitudinally of said cathode with respect to saidplurality of electrodes, and collector electrode means surrounding saidcathode and said control electrodes.

6. An electric discharge device comprising an elongated cathode, aplurality of radially extending control electrodes supported in mutuallyspaced and insulated relation in a circular array concentric with saidcathode and lying in a plane i 10 directed inwardly and terminating inspaced relation, a cathode supported centrally in the openings definedby said flanges, and a coil surrounding said members for producing aflux in the gap between said flanges to control the electrons emitted bysaid cathode.

8. An electric discharge device comprising a substantially cylindricalcollector electrode, a pair of members of magnetic material eachincluding a marginal planar portion and a central flange portiondefining an opening of gradually decreasing cross section, said membersbeing supported at opposite ends of said electrode with said flangesdirected inwardly and terminating in spaced relation, a cathodesupported centrally in the openings defined by said flanges, and a pairof control electrode assemblies supported respectively in the openingsdefined by said members and between said cathode and said collectorelectrode. 1

9. An electrode assembly comprising a disklike member of magneticmaterial having a contrally located aperture defined by a flange ofgradually decreasing diameter, an electrode assembly supported from saidmember and extending within said opening including a cylindricalelectrode, an insulating spacer member surrounding said cylindricalelectrode and engaging the inner Wall of said flange, and a disk-likeelectrode secured in engagement with said insulating spacer and inconcentric relation with said cylindrical electrode.

10. A polyphase electrode assembly comprising an. insulating cylinder, aplurality of wire-like r electrode elements each element including aradial portion extending across a portion of one end of said cylinderand an axial portion lying along'the outer surface of said cylinder,said .elements being supported in uniformly spaced relation with thelongitudinal portions of adjacent elements extending along thesurface ofthe cylinder at different distances, said conductors being arranged insymmetrical groups having longitudinal portions of equal lengths, aplurality of conductive washers surrounding said cylinder and supportedin spaced insulated relation, the conductors of each group, beingconnected with a different one of the washers,

. '11. An electric discharge device system comprising cylindricalcollector electrode means including mutually insulated complementarycollecting surfaces, a source of electrons including means for confiningsaid electrons in a relatively narrow region in the direction of theaxis of said cylinder, a polyphase deflecting electrode system supportedon one side of said region from said source and said collector electrodemeans, an electrode supported on the opposite side of said region, apolyphase supply of carrier voltage including a neutral connection, andmeans energizing said polyphase electrode system with the phase voltageof said supply and said electrode with the voltage of said neutralconnection.

12. An electric discharge device system comprising cylindrical collectorelectrode means including mutually insulated complementary collectingsurfaces, a source of electrons including means for confining saidelectrons in a relatively narrow region in the direction of the axis ofsaid cylinder, a polyphase deflecting electrode system supported on oneside of said region and between said source and said collector electrodemeans, an electrode supported on the opposite side of said region, apolyphase supply of car- I 1. rler voltage including a neutralconnection, means energizing said polyphase electrode system'with "thephase voltagesof said supply and said electrode with the voltage of saidneutral connection, and means comprising a unidirectional bias voltagebetween. said neutralconnectionand said electrode.

13. In combination, cylindrical collector electrode means includingmutually insulated complementary collecting surfaces-a source ofelectrons including means'for confiningsaid electrons in'a relativelynarrow region'in the direction of the axis of said'cylinder, apolyphase' deflecting electrode system supported between said source andsaid collector electrode means for producing a repetitive deflection ofelectrons provided 'by said source from one of said surfaces toitheother, and a self-biasing circuit connected with one of said surfaces tomaintain it at a substantial negative voltage with respect to the otherof said surfaces; 14. An electric discharge device comprising a pair ofconcentrically arranged cylindrical collecting electrodes, 2. pair. ofapertured disks of insulating material positioned respectively onopposite ends of said electrodes, a pair of members of magneticmaterial, each of said mem-- bers comprising a marginal planar portionand a central flange portion defining a central opening,

said members being assembled on said disks with said flangesextendinginwardly through the apertures of said disks and terminating in spacedrelation to provide a central gap,-'and a cathode supported within theopening defined by said 15.'An electric discharge. device comprising acentral opening, said members being assembled I respectively on saiddisks with said marginal portions in parallel relation and said flangesextending inwardly throughthe" apertures in said disks and terminatingin spaced relation, a cathode supported centrally within the openingdefined by said flanges, control electrode means '12 positioned betweensaid cathode and said flanges for producing a deflection of theelectrons emitted by said cathode and in an axial direction with respectto said cylindrical electrodes, and means cooperating with said membersof magnetic material for producing a magnetic field between the ends ofsaid flanges.

16. An electric discharge device comprising a pair of concentricallyarranged cylindrical collecting electrodes, a pair of members ofmagnetic material, each of said members comprising a marginal planarportion and a central flange extending generally perpendicular to saidmarginal portion anddefining-acentral opening, said members beingassembled respectively on opposite ends of said cylindrical collectingelectrodes with said marginal portions in parallel relation and withsaid-flanges extending inwardly and terminating in spaced relation toprovide a control gap, a cathode supported within the opening defined bysaid flanges, and control electrode means positioned between saidcathode and said flanges for producing a'deflection of the electronsemitted by said cathode and in an axial direction with respect to saidcylindrical electrodes.

17. A three-phase cylindrical electrode system for collecting electronsselectively in accordance with a repetitive displacement of theelectrons in an axial direction comprising a cylindrical electrodehaving three sets of openings with each opening having a widthcorresponding to 180 at a predetermined frequency and with the firstopening of the second and third groups displaced a distancecorresponding, to 120 electrical degrees at said frequency with respectto the last opening of the preceding group, and three mutually insulatedelectrode means supported outside of said cylindrical electrode.

FRANCIS M.

REFERENCES CITED UNITED STATES PA'in 'rs BAILEY.

Number Name Date 2,129,710 Soller; Sept. 23, 1938 2,151,765 Hellman Mar.28, 1939 2,322,556 Ziebolz June 22, 1943 2,391,967 Hecht et al Jan. 1,1946

